balboa bp2000g1 with a tp900 expansion pump(s) issue

[podymfd]

I've retrofit an older swimspa with a new bp2000g1.  I've also installed a new tp900 topside to control it.  All wiring is correct and verified.  When the system starts up in prime mode, all my pumps are visible and work correctly.  Once I exit prime mode, pumps 3 and 4 (connected to the extender board) disappear.   I can rotate which pumps are plugged in where and the issue follows the extender.  I can't find any information about menu programming that needs done.  All paperwork says the display will show "all available accessories".  Presently, the unit is running in mode 7 2spd,1spd,1spd,1spd.   I've tried other modes, with the same results.  Thoughts?

Thanks in advance,

Matt